Blower wheel



March 5, 1963 K. A. MERZ BLOWER WHEEL Original Filed Nov. 21, 1955 FIGQ5M INVENTOR. KENNETH A. MERZ Wu m c ATTORNEY United States Patent Ofifice3,880,105 Patented Mar. 5, 1963 3,080,105 BLOWER WHEEL Kenneth A. Merz,Cornwall, Conn., assignor to The Torrington Manufacturing Company,Torrington, Cnn., a corporation of Connecticut Original application Nov.21, 1955, Ser. No. 548,166, now Patent No. 3,004,326, dated Oct. 17,1961. Divided and this application Oct. 30, 1959, Ser. No. 849,888

Claims. (Cl. 230-134) This application is a division of my applicationSerial No. 548,166 filed November 21, 1955, now Patent No. 3,004,326,and entitled Support Structure and Method for Making a Blower Wheel, thelast said application being a continuation-in-part of my priorapplication Serial No. 441,612 filed July 6, 1954 for Blower Wheel andMethod of Making, now abandoned.

The invention relates to a blower wheel of the type wherein there is anannular series of longitudinal air moving blades and wherein there is agenerally radial structure engaging the blades between the ends thereofto connect them with a central hub or hub means.

One object of the invention is to provide a. simple, dependable andinexpensive connection between the radial structure and the blades forholding the blades in fixed relationship with the said radial structure.

In the drawing I have shown in detail alternative blower wheelsembodying the invention, but it will be understood that various changesmay be made from the constructions shown, and that the drawing is not tobe construed as defining or limiting the scope of the invention, theclaims forming a part of this specification being relied upon for thatpurpose.

Of the drawing:

FIG. 1 is a vertical longitudinal sectional view of a blower wheelembodying the invention.

FIG. 2 is a fragmentary transverse sectional view taken along the line22 of FIG. 1.

FIG. 3 is an enlarged fragmentary transverse sectional view taken alongthe line 33 of FIG. 1.

FIG. 4 is an enlarged fragmentary sectional view taken along the line4-4 of FIG. 2.

FIG. 5 is an enlarged fragmentary sectional view taken along the line 55of FIG. 4 but showing the parts in an intermediate stage in the methodof making the blower wheel.

FIG. 6 is a view similar to FIG. 5 but showing the parts in finalpositions.

FIG. 7 is an enlarged fragmentary sectional View taken along the line7-7 of FIG. 4.

FIG. 8 is a view similar to FIG. 5 but showing alternative structuralfeatures.

FIG. 9 is a view similar to FIG. 6 but showing the same alternativefeatures as shown in FIG. 8.

Referring to the drawing and more particularly to FIGS. 1 to 7 thereof,the blower wheel as illustrated includes a hub means which is shown ascomprising two separate similar hubs 10 and 12. When the hub meanscomprises two hubs such as 10 and 12, the two hubs are in longitudinalregister with each other and are rotatable about the same longitudinalaxis. They are adapted for mounting on a rotatable shaft and as shownset screws 14 and 16 are provided for connecting the hubs with theshaft. At least one generally radial supporting member or disc 18 isprovided, this disc having its inner portion rigidly connected with thehubs means. A second supporting member or disc 20 is also provided andthis is preferably similar to the disc 18. When there are two similardiscs they are rigidly connected respectively with the two hubs 10 and12. The discs 18 and 20 are connected with each other near theirperipheries as for instance by spot welding, as indicated at 22, 22. The

discs 18 and 20 are preferably partly conical in shape so that the hubs10 and 12 are spaced apart longitudinally and so that the portions ofthe discs adjacent the hubs converge toward their connected peripheralportions. One or more drain holes such as 24 may be provided in at leastone of the discs to permit the escape of water which might otherwiseaccumulate in the space between the discs. The discs 18 and 20 are shownas being identical in construction but in relatively reversed positions.

The blower wheel includes an annular series of equally spacedlongitudinal air moving blades 26, 26, the said series being concentricwith the axis and the blades of the said series being adjacent theperiphery of the disc or discs. The blades 26, 26 may have any usual orpreferred cross-sectional shape and the shape of the blades does notconstitute any part of the present invention. The blades are shown asbeing structurally separate from each other, but the invention is notnecessarily so limited.

Means are provided at the ends of the blades for connecting them witheach other, these means being shown as being two similar end rings 28and 30. The details of connection between the blades and the end ringsmay be in accordance with conventional practice and do not constituteany part of the present invention. The blades 26, 26 are formedrespectively with notches 32 near their centers, the several notchesbeing arranged in an annular series, each notch extends outwardly fromthe inner edge of the corresponding blade and has opposite outwardlyextending lateral edges 34, 34 which preferably diverge outwardly. Asshown, the edges 34, 34 of each notch 32 are straight and are equallyinclined in opposite directions from a central radial plane, but as tothese details there may be substantial variation.

The disc 18 has an annular peripheral portion 36 which is located in thenotches 32 of the several blades. The supporting member additional tothe disc 18 has an annular peripheral portion 3-8 that is also locatedin the said notches 32. When the additional means or member is a seconddisc such as 28, the said portion 38 is a peripheral portion similar tothe peripheral portion 36 of the disc 18. In the blower wheel as shownin FIG. 1, the supporting members or discs are in direct engagement witheach other along an annular zone which is immediately adjacent the inneredges of the blades and the annular peripheral portions 36 and 38 of thesupporting members or discs that are radially outside of said annularzone and are located in said notches are spaced apart and they divergeoutwardly. Said peripheral portions are respectively in engagement underpressure with the opposite outwardly extending edges of said notches 32in the blades 26.

During manufacture, pressure is applied to said two supporting discs 18and 20 to cause said peripheral portions 36 and 38 thereof to swing awayfrom each other and outwardly diverge so that said annular peripheralportions 36 and 38 have the aforesaid pressure engagement respectivelywith the opposite edges of the blade notches 32 so as to firmly hold theblades 26 in fixed relationship to said discs 18 and 20. As shown inFIG. 5 at least one of the supporting members or discs 18 and 20 isinitially formed with an annular bead such as 40, this head beingadjacent and spaced inwardly from the corresponding peripheral portion36. The bead 40 on one disc projects away from the other disc.Preferably and as shown, the two members or discs 18 and 20 have similaroppositely projecting annular beads 40 and 42 adjacent and spacedinwardly from the peripheral portions 36 and 38. The members or discs 18and 20 have inner annular portions at least approximately in contactwith each other and located adjacent the inner edges of the beads.

In making the blower wheel the discs 13 and 20 are connected with thehubs It? and 12 and the discs are con nected with each other, aspreviously described. The said discs with their annular beads and thesaid hub means collectively constitute an initial central supportstructure for the blower wheel.

The blades 26, 26 are assembled with the support structure, the bladesbeing assembled so that the peripheral portions 36 and 38 are located inthe notches 32 as shown in FIG. 5. The outer edges of the beads 46 and42 are closely adjacent the inner edges of the blades 26, but arenevertheless spaced inwardly therefrom to a small extent. The assembledparts are preferably held temporarily in a suitable fixture so that theannular series of blades is concentric with the axis of the hubs.Thereafter the end rings 28 and 30 are put in place so as to connect theblades with each other and thus hold them in their proper spacedrelationship.

After preliminary assembly as described, the bead 49 or both beads 46and 42 are subjected to longitudinal pressure throughout their entirelengths. The beads are at least partly flattened, being changed from theshapes shown in FIG. to the shapes shown in FIG. 6. Thepartialflattcning of each head resultantly causes the correspondingperipheral portion to swing away from the other peripheral portion and,when there are two heads such as 40 and 42 and two peripheral portionssuch as 36 and 38, said peripheral portions swing away from each other.At the same time the diameters of the discs are slightly increased sothat the outer edges of the beads 40 and 42 move closer to the inneredges of the blades 26 as shown in FIG. 6. The described swingingmovements of one or both of the peripheral portions 36 and 38 cause themto outwardly diverge and to engage the edges 34, 34 of the several bladenotches as shown in FIG. 6, the blades and the discs being thus firmlyconnected with each other. When the notch edges outwardly diverge, as ispreferred, the outwardly diverging peripheral portions 36 and 38 engageand fit said notch edges 34, 34 throughout major parts of the lengthsthereof.

When the peripheral portions of the members or discs engage the edges ofthe blade notches 34, 34 as shown in FIG. 6, the applied longitudinalpressure is continued and the swinging movements of the peripheralportions tend to continue beyond the positions shown, but said swingingmovements are limited by the engagement of said peripheral portions withthe opposite edges of the blade notches 34, 34. As the result of saidlimitation of the swinging movements of the peripheral portions, saidmembers or discs are so stressed that they inherently cause saidengagement of the peripheral portions with the opposite edges of theseveral notches to be under pressure. Between the blades the swingingmovements are not imited by direct engagement with the blades and theperipheral portions between the blades swing away from each other togreater extents as shown in FIG. 7. The outer edges of the peripheralportions therefor undulate as shown in FIG. 4. It will be seen that thesaid peripheral portions 36 and 38 have a divergence between the bladeswhich is greater than the divergence at the blades. Thus the peripheralportions of the members or discs tend to hold the blades in properspaced relationship.

Preferably at least one of the members or discs 18 and 20 is providedwith peripheral notches 44, 44 spaced in accordance with the spacing ofthe blades 26, 26. The notches 44, 44 are shaped to accommodate thecurvature of the blades, as shown in FIG. 3. As shown both discs 18 and20 are provided with notches 44, 44, the notches in the two discs beingin register with each other. During initial assembly, the blade portionsadjacent the outer edges of the blade notches 32 are entered in the discnotches as shown in FIGS. 3 and 5. When the discs are deformed from theFIG. 5 shape to the FIG. 6 shape, the said portions of the blades remainat least partly en- 4 tered in the disc notches as shown in FIG. 6. Thusthe notches in the discs cooperate with the undulating peripheral shapesof the discs to positively hold the blade in proper spaced relationship.

FIGS. 8 and 9 are similar respectively to FIGS. 5 and 6 but theyillustrate the fact that one of the two discs or supporting members maybe flat and without any bead such as 41) or 42.

As shown in FIG. 8, a disc 18 is provided which is or may be exactly.the same as the disc 18 shown in FIG. 5. In lieu of the beaded disc 20there is provided a flat disc 46 which need not be directly connectedwith the hub means, but which is shown as having a large central openingand as being connected by welding or otherwise to the disc 18, theconnection being near the edge of said opening. The disc 46 is entirelyflat and the diameter of its peripheral portion 48 is the same as thediameter of the disc 18 at the bottoms of the notches 44.

Alternative blades 50 are provided having notches 52 which are similarto the notches 32 except that the edge 54 at the left is perpendicularinstead of inclined.

After preliminary assembly as previously described, the bead 40 of thedisc 18 is subject to longitudinal pressure and the head is at leastpartly flattened as shown in FIG. 9. The partial flattening of said headresultantly causes the peripheral portion 36 of the disc 18 to swingaway from the peripheral portion 48 of the disc 45. At the same time thediameter of the disc 18 is slightly increased. The described swingingmovement of the portion 36 of the disc 18 away from the peripheralportion 43 of the disc 46 causes said peripheral portions to outwardlydiverge and to engage the outwardly diverging edges of the blade notches52 as shown in FIG. 9, the blades and the discs being thus firmlyconnected with each other. The peripheral portions of the discs are inengagegnzent 2pnder pressure with the edges of the blade notches Theinvention claimed is:

1. In a centrifugal blower wheel, the combination of a hub meansrotatable about a central longitudinal axis and adapted for mounting ona rotatable shaft, an aunular series of equally spaced axially extendingair moving blades which annular series is concentric with the axis ofthe hub means, the blades of said series having opposite radially spacedinner and outer edges and also having axially spaced opposite ends, andsaid blades being formed with notches arranged in an annular series andeach said notch extending outwardly from the inner edge of its blade andeach said notch having opposite outwardly extending and outwardlydiverging lateral edges, means at said opposite ends of the blades forconnecting them with each other, and two separate generally radial sheetmetal supporting members rigidly connected with the hub means andextending radially outwardly therefrom, said supporting members havingperipheral portions located in said notches in the blades and saidmembers being in direct engagement with each other along an annular zoneimmediately adjacent and inwardly of the inner edges of the blades andthe entire annular peripheral portions of said members that are radiallyoutside of said annular zone being spaced apart and diverging outwardlyand respectively in engagement with the opposite outwardly divergingedges of the several notches in the blades throughout the major parts ofthe lengths of said edges and said supporting members being so stressedthat they inherently cause said engagement with the notch edges to beunder pressure.

2. In a centrifugal blower wheel, the combination of a hub meansrotatable about a central longitudinal axis and adapted for mounting ona rotatable shaft, an annular series of equally spaced axially extendingair moving blades which annular series is concentric with the axis ofthe hub means, the blades of said series having opposite radially spacedinner and outer edges and also having axially spaced opposite ends, andsaid blades being formed with notches arranged in an annular series andeach said notch extending outwardly from the inner edge of its blade andeach said notch having opposite outwardly extending lateral edges whichdiverge outwardly and to equal extents from a central planeperpendicular to the axis, means at said opposite ends of the blades forconnecting them with each other, and two separate similar generallyradial sheet metal supporting discs each rigidly connected with the hubmeans and extending radially outwardly therefrom, said supporting discshaving peripheral portions located in said notches in the blades andsaid discs being in direct engagement with each other along an annularZone immediately adjacent and inwardly of the inner edges of the bladesand the entire annular peripheral portions of said discs that areradially outside of said annular zone being spaced apart and divergingoutwardly and to equal extents from a central plane perpendicular to theaxis, and respectively in engagement with the opposite outward-1ydiverging edges of the several notches in the blades through the majorparts of the lengths of said edges and said discs being so stressed thatthey inherently cause said engagement with the notch edges to be underpressure.

3. In a centrifugal blower wheel, the combination of a hub meansrotatable about a central longitudinal axis and adapted for mounting ona rotatable shaft, an annular series of eqully spaced axially extendingair moving blades which annular series is concentric with the axis ofthe hub means, the blades of said series having opposite radially spacedinner and outer edges and also having axially spaced opposite ends, andsaid blades being formed with notches arranged in an annular series andeach said notch extending outwardly from the inner edge of its blade andeach said notch having opposite outwardly extending and outwardlydiverging lateral edges, means at said opposite ends of the blades forconnecting them with each other, and two similar generally radial sheetmetal supporting discs rigidly connected with each other and havinginner portions rigidly connected with the hub means and having annularperipheral portions located in said notches in the blades, said annularperipheral portions of the discs being spaced apart and divergingoutwardly and respectively in engagement under pressure with theopposite outwardly diverging edges of the notches in the bladesthroughout the major parts of the lengths of said edges so as to connectthe blades with the discs and said annular peripheral portions of saiddiscs having a divergence between the blades greater than the divergenceat the blades so that the greater divergence between the blades tends tomaintain the blades in equally spaced relationship.

4. In a centrifugal blower wheel, the combination of a hub meansrotatable about a central longitudinal axis and adapted for mounting ona rotatable shaft, an annular series of eqully spaced axially extendingair moving blades which annular series is concentric with the axis ofthe hub means, the blades of said series having opposite radially spacedinner and outer edges and also having axially spaced opposite ends, andsaid blades being formed with notches arranged in an annular series andeach said notch extending outwardly from the inner edge of its blade andeach said notch having outwardly extending and outwardly diverginglateral edges, means at said opposite ends of the blades for connectingthem with each other, and two similar generally radial supporting discshaving their inner portions rigidly connected with the hub means, thesaid two discs having annular peripheral portions located in the saidnotches in the blades and said annular peripheral portions of the discsbeing spaced apart and outwardly diverging and respectively inengagement under pressure with the outwardly diverging edges of saidnotches and at least one of said discs having notches in its peripheryequally spaced to receive and approximately fit the blade portionsadjacent the outer edges of the blade notches so that said disc notchestend to maintain the blades in equally spaced relationship.

5. In a centrifugal blower wheel, the combination of a hub meansrotatable about a central longitudinal axis and adapted for mounting ona rotatable shaft, an annular series of eqully spaced axially extendingair moving blades which annular series is concentric with the axis ofthe hub means, the blades of said series having opposite radially spacedinner and outer edges and also having axially spaced opposite ends, andsaid blades being formed with notches arranged in an annular series andeach said notch extending outwardly from the inner edge of its blade andeach said notch having outwardly diverging lateral edges, means at saidopposite ends of the blades for connecting them with each other, and twosimilar generally radial sheet metal supporting discs rigidly connectedwith each other and having inner portions rigidly connected with the hubmeans and having annular peripheral portions located in the said notchesin the blades, said annular peripheral portions of the discs beingspaced apart and diverging outwardly and respectively in engagementunder pressure with the outwardly diverging edges of the notches in theblades so as to connect the blades with the discs and said annularperipheral portions having a divergence between the blades greater thanthe divergence at the blades so that the greater divergence between theblades tends to maintain the blades in equally spaced relationship andat least one of the said discs having notches in its periphery equallyspaced to receive and approximately fit the blade portions adjacent theouter edges of the blade notches so that said disc notches cooperatewith the greater divergence of the peripheral portions of the discsbetween the blades to maintain the blades in equally spacedrelationship.

References Cited in the file of this patent UNITED STATES PATENTS478,191 Hide July 5, 1892 886,515 Jude May 5, 1908 903,532 Anderson Nov.10, 1908 931,403 Fleming Aug. 17, 1909 978,036 Klahn Dec. 6, 19101,377,634 Slick May 10, 1921 1,748,452 Martins Feb. 25, 1930 2,125,697Swingle et al. Aug. 2, 1938 2,240,238 Baker Apr. 29, 1941 2,304,581 LyonDec. 8, 1942 2,315,407 Evans Mar. 30, 1943 2,537,805 Wilken Jan. 9, 19512,825,124 Nichols et al. Mar. 4, 1958 3,021,591 Mayne et al. Feb. 20,1962 FOREIGN PATENTS 294,629 Great Britain Feb. 14, 1924

1. IN A CENTRIFUGAL BLOWER WHEEL, THE COMBINATION OF A HUB MEANSROTATABLE ABOUT A CENTRAL LONGITUDINAL AXIS AND ADAPTED FOR MOUNTING ONA ROTATABLE SHAFT, AN ANNULAR SERIES OF EQUALLY SPACED AXIALLY EXTENDINGAIR MOVING BLADES WHICH ANNULAR SERIES IS CONCENTRIC WITH THE AXIS OFTHE HUB MEANS, THE BLADES OF SAID SERIES HAVING OPPOSITE RADIALLY SPACEDINNER AND OUTER EDGES AND ALSO HAVING AXIALLY SPACED OPPOSITE ENDS, ANDSAID BLADES BEING FORMED WITH NOTCHES ARRANGED IN AN ANNULAR SERIES ANDEACH SAID NOTCH EXTENDING OUTWARDLY FROM THE INNER EDGE OF ITS BLADE ANDEACH SAID NOTCH HAVING OPPOSITE OUTWARDLY EXTENDING AND OUTWARDLYDIVERGING LATERAL EDGES, MEANS AT SAID OPPOSITE ENDS OF THE BLADES FORCONNECTING THEM WITH EACH OTHER, AND TWO SEPARATE GENERALLY RADIAL SHEETMETAL SUPPORTING MEMBERS RIGIDLY CONNECTED WITH THE HUB MEANS ANDEXTENDING RADIALLY OUTWARDLY THEREFROM, SAID SUPPORTING MEMBERS HAVINGPERIPHERAL PORTIONS LOCATED IN SAID NOTCHES IN THE BLADES AND SAIDMEMBERS BEING IN DIRECT ENGAGEMENT WITH EACH OTHER ALONG AN ANNULAR ZONEIMMEDIATELY ADJACENT AND INWARDLY OF THE INNER EDGES OF THE BLADES ANDTHE ENTIRE ANNULAR PERIPHERAL PORTIONS OF SAID MEMBERS THAT ARE RADIALLYOUTSIDE OF SAID ANNULAR ZONE BEING SPACED APART AND DIVERGING OUTWARDLYAND RESPECTIVELY IN ENGAGEMENT WITH THE OPPOSITE OUTWARDLY DIVERGINGEDGES OF THE SEVERAL NOTCHES IN THE BLADES THROUGHOUT THE MAJOR PARTS OFTHE LENGTHS OF SAID EDGES AND SAID SUPPORTING MEMBERS BEING SO STRESSEDTHAT THEY INHERENTLY CAUSE SAID ENGAGEMENT WITH THE NOTCH EDGES TO BEUNDER PRESSURE.